Method of and apparatus for treating hydrocarbons



' Aug, 5, 1930 V1 E. WELLMAN 1,773,333I

METHOD OF AND APPARATUS FOR TREATING HYDROCARBONS Filed Feb. 29, 1928 flming. s, 1930 1,772,331

UNITED STATES PATENT orrlcr.

FRANK E. WELLMAN, OF KANSAS CITY, KANSAS METHOD OF APPARATUS FORTREATING HYDROCABBONS I p 1 Application flied February 29, 1828. SerialNo. 257,942.

My invention relates to methods of and sure which'drops in the condenser7 and onl v apparatus for treatment ofhydrocarbon oils, a relatively lowpressure is carried through Y and has for its object to recover theexpanand beyond the condenser. The expansive sive energy which is nowemployed in such force represented by the pressure in pipe 4 5 methodsand apparatus, and then lost. in this case is lost. 65

In systems for the refining of hydrocarbon I Examples might bemultiplied indefinitely, oils in cracking plants, and elsewhere, it isas apparently no such efl'ort has been made to common to heat the oil toproduce vapors conserve the pressure energy as there has been which arepassed through a suitable pipe line to conserve heat energy, although,as already from the still orretort to a dephlegmator or pointed out, itrepresents a serious loss. 60 bubble tower on other apparatus. accordingto According to my present invention, and in the treatment being carriedon. The temperaorder to attain my object, I connect a motor in tures andpressures employed in these systhe-vapor line or other portion of thesystem terms are frequently very high, a. pressure of carrying pressureand preceding a pressure 600 lbs. to the square inch being notuncomdrop, so that there can be no interference mon. These temperaturesand pressures, with the normal operation. Accordin to after they haveperformed their useful func- What I now consider the best method oftions, in point of energy dissipated are very utilizlng this power, Icouple. this motor, wasteful. Thus, in large plants of a certain whichmay convenientlybe a turbine, to a type, the power which goes to wasteprobably generator, and transmit power electrically to amounts to 100horsepower. In many plants, points of utilization in the plant. Suchturboheat energy is recovered to a certain extent, generator units havebeen developed to a usually by the use of heat exchangers, counterpointof high efficiency, and are well known current circulators, or bubbletowers. So far in the art. ()f'course, as a modification, it as I amaware, however, nothing of effort is possible to transmit the powermechanically 75 has been made to recover the energy repreand utilize itmechanically, but I have found a sented by the expansive forces due tothe pres electrical transmission better for my purposes sure imposedupon the gases and liquids in because it is more flexible and is in linewith the course of their treatment, and especially modern standardpractice. in the initial or primary distillation and Another veryimportant use which is inso 'cracking thereof. cluded within the scopeof my invention is In every such system there are numerous that ofsupplying supplemental heat either applications of power, includingpumps for to a cracking still or to a preheater. By ear the make-up,pressure pumps and pieces of ploying an electric generator unit, it 1smy retreatment apparatus, pumps for forcing purpose to produce currentwhich may be reflux back into the header of a cracking resupplied to allthe needs of the lam, intort or pressure still, fans or blowers forcludlng pumps, recirculation of no gases, recirculating flue gases, andelectric lighting lighting and the like, and thereafter if thereapparatus. Power is usually supplied for be any margin of power left, toadd the 40 these from outside sources. V, same in the form of heat toraise the tempera- Specifically stated, my invention has for ture ofstills, preheaters and the like. its object to recover the energyrepresented My invention is illustrated in the accomby the expansiveforce due to pressure in any panying drawing, in which the figure is apart of a system of the class mentioned and diagram showing a system forthe treatment return it in the form of useful work into the ofhydrocarbon oils, including a cracking still system, or otherwiseusefully employ it. For and reflux line operated under high pressure,example, in a system such as that shown in with my invention appliedthereto. U. S. Letters Patent No. 1,119,700, granted Referring'to thedrawing, 1 is a substruc- December 1, 1914, to R. E. Humphreys, the tureor base, containing flue 2 leading to a vapor line 4 carries asuper-atmospheric presstack and supporting a cracking still 3, fromwhich a reflux line 4; extends obliquely upward to an elevated pointwhere it is fitted with a pressure control valve 5, from which pipe 16drops to a condenser 7 from which the outlet pipe 9 extends to areceiver 8. In the upper part of thesubstructure is a furnace 1U, fittedwith the usual oil burner 11 and fine 2, already mentioned, extending toa stack 12.

In operation, the still 3 is charged with a heavy hydrocarbon liquid,heat is applied thereto, and vapors pass up through the line 4, whereinthe heavier fractions are condensed and reflux back into the still forretreatment. The valve 5 is kept closed until the desired operatingpressure is obtained, after which it serves to control the pressure andto permit the passage of the lighter fractions suitable for condensationand storage. The drop in pressure outside of the valve 5 is produced byexpanding the vapors and condensing them in the condenser 7, and theenergy represented by the expansive force due to pressure controlled bythe valve 5 is in prior practice dissipated largely as heat in thecooling water, and is thereby lost.

According to my present invention I install a turbo-generator unit 13with a turbine 14 whose intake 15 is connected to the reflux line 4through the valve 5, and whose exhaust 16 is connected to the condenser7. The generator 17 may conveniently be an alternator of standardconstruction, indicated as furnishing current at 220 volts to the mains18, which may supply feeders leading to various points in the plant. Ihave shown an electric lighting circuit 19 thus supplied with current,and a power circuit 20 extending to a motor 21 driving a blower 22 forcirculating flue gases, to be presently described. and an electricheater 23 installed in the still 3 for the purpose of returning aportion of the energy in the form of heat to the oil itself.

The circulation of flue gases in the Present case is accomplished asfollows: The furnace 10 has a flue 2 extending to the stack 12. At anindifferent point, such as 24, in the flue 2, a breeching 25 is takenoff to the blower 22 and continues therefrom to the furnace 10. Inoperation, the heated gases and products of combustion pass from thefurnace through the fine 2 to the stack 12, but the blower 22 draws offa certain portion of them through the breeching 25 and conveys them backto the furnace 10 to be mingled therein with the hot gases and productsof combustion from the burner 11 and thereby to soften the heat appliedto the still. The relation between the total volume of gases passingthrough the flue-2 and the volume that is withdrawn at the point 24 maybe varied, and is a matter of design, depending upon the capacity of theblower. These blowers are usually operated by motors under energysupplied from outside the system. According to my invention I connectthe motor 21 through circuit 20 to the mains 18, to derive power fromthe generator 17.

Usually the amount of energy derivable from the drop in pressure betweenthe reflux pipe and the condenser is sutlicient for the circulation ofthe flue gases, but in case a larger amount of energy is available Iemploy it in supplemental heating of the oil in the still For thispurpose an enclosed heating unit is mounted in the still and its circuitconnected through the insulating bushing 26 to the circuit 20. By thismeans the energy represented in expansive force in the vapors leavingthe still under pressure is rest red to the oil in the form of heat.

Rv a modification of this electric heating moihtul. the heating unit 23or its equivalent may llt applied to the reflux line 4 so as tosupcrhcut the vapors therein, with the result of increased cracking inthe vapor phase. I have not illustrated this species of the invention,because it will be clearly understood from the illustration given. It isto be noted, however, that the form of the heater may be changed invarious ways, as for example by aiiplying heating coils to the pipe 4,and the li e.

It is unnecessary for the purposes of this specification to describe thepieces of apparatus in detail, as standard units are available in eachcase. and the structure and arrangement mav be varied and modifiedwithout departing from the scope and purview of the invention. providedthey are adapted to my use and suitable for my purpose, as herein setforth.

Having thus described my invention. what I claim and desire to secure byLetters Pa ent is:

1. In treating hydrocarbon oils, the method of conserving energy whichconsists heating said oils in a closed vessel to produce crackingtemperature and pressure therein conducting the vapors from said stillwhile under ressure through a vapor line, expanding said vapors and asesthrough a suitable motor so as to produce mechanical power, and causingsaid power to resunply the energv so recovered in the form of heat tothe oil be ng treated.

2. The method described in claim 1, in which the vapors and gases arecaused to pass from the high pressure vapor line and be ex- 31 pandedthrough a suitable motor into a cond nsing zone. and the energvdeveloped in the motor thereby is caused to produce heat. which iscontinuously resupplied to the oil under treatment.

3. The method described in claim 1, which includes the step of expandingthe vapors and gases from a high pressure vapor line through a suitablemotor, causing the power developed in said motor to generate an electriccurrent, and applying the energy in said electric current to produceheat in the oil under treatment.

4. The method of conserving energy rep- 5 resented by the expansiveforce due to compression in a system for treating hydrocarbon oils'asdescribed in claim 1, which consists in expanding the vapors and gasesthrough a suitable motor at a point of natural pressure drop in thesystem so as to generate mechanical power, and then causing said powerto restore to the oil under treatment in the form of heat the energylost in expansion.

5. In a system for the treatment of hydrocarbon oils, a still, a highpressure vapor line and alow pressure condenser adapted to re- 1 ceivevapors from said vapor line and forming an expansion chamber therefor, amotor connected so as to utilize the drop in pressure from said vaporline into said condenser, an electric generator connected to be drivenby said motor, and translating devices connected to receive electricalenergy from said generator and to transform the same into heat in theoil under treatment.

In testimony whereof I hereunto aifix my signature.

FRANK E. WELLMAN.

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